关键词: 语义, 自动服务组合, 图搜索, 匹配, 组合结构, Web服务

Abstract: The method based on graph search was a simple and direct way to realize the Web service automatic composition，but the search space was too large and it was difficult to express various combination structures among services.To solve this problem，a method based on semantic matching relationship to determine combination structure was presented.Formal description of the Web services semantics were presented，and then based on semantic matching relationship，the semantic relationship graph was established by services which were only related to user provided input and expected output.On this basis，various combination structure models were defined based on semantic matching relationship，and taking integrated semantic matching degree as optimal goal，the breadth-first search algorithm was improved，the calculation method of semantic matching degree in various combination structure was defined，and the service combination path which owned the optimal integrated semantic matching degree was generated.The feasibility of proposed algorithm was verified though an example.　

Key words: semantics, automatic service composition, graph search, matching, composition structure, Web service